Genetic mapping of resistance to southern corn rust (Puccinia polysora underw.) of maize
KrishiKosh
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Title |
Genetic mapping of resistance to southern corn rust (Puccinia polysora underw.) of maize
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Creator |
P, Bhavani
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Contributor |
K. M, Harinikumar
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Subject |
genes, diseases, maize, chromosomes, genetics, planting, plant oils, yields, genomes, proteins
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Description |
Southern corn rust (SCR) is a major disease of maize whose periodic nature has rendered breeding for resistance a challenging task. There is a need to identify tightly linked molecular markers to enhance breeding efficacy. F2:3 mapping population derived by crossing two inbreds namely SKV50 (resistant) with CM202 (susceptible) was used in the study. The population manifested high genotypic and phenotypic variability for grain yield and SCR resistance. Grain yield, cob length and SCR resistance exhibited high heritability coupled with GA percent of mean. Chi square analysis revealed dominance inheritance of the gene governing resistance to SCR. An integrated map for bin 10.01 involving genetic elements Rpp9, RppQ, RppD and linked SSR & BACs within the contig 392 was developed using Maize GDB. Genes identified within the contig using Fgenesh (in bits of 1 MB) were subjected to BLAST. Orthologs loci manifesting high degree of similarity with genomes of rice, sorghum and brachypodium grass harbouring genes associated with disease resistance were obtained. 25 genes were shortlisted for primer designing and further analyses. Seven SSRs flanking the reported resistance genes were also included. Four genes viz., Pp2 (phytoene synthase), Pp7 (phytosulphokines), Myb2 (transcription factor), Psk (phytosulphokines) displayed polymorphism between parents and were subsequently used for screening the F2 mapping population. Among these, Pp7 and Pp2 showed association with the SCR resistance. In this study the co-localization of genetic elements of SCR, locus for common rust resistance and annotated functional genes along with candidate gene primers Pp7 and Pp2 encoding phytosulfokines and phytoene synthase respectively has been shown. |
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Date |
2016-05-19T13:58:54Z
2016-05-19T13:58:54Z 2013-01-29 |
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Type |
Thesis
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Identifier |
Th-10455
http://krishikosh.egranth.ac.in/handle/1/66134 |
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Language |
en
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Format |
application/pdf
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Publisher |
University of Agricultural Sciences, Bengaluru
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